In midsummer of 1943, during a long heat wave, the RAF, supported by the United States Eighth Army Air Force, flew a series of raids on Hamburg. The aim of Operation Gomorrah, as it was called, was to destroy the city and reduce it to ashes. In a raid early in the morning of July 28, beginning at 1am, thousands of tonnes of high-explosive and incendiary bombs were dropped on the densely populated residential area north of the Elbe. A now familiar sequence of events occurred: first, all the doors and windows were torn from their frames and smashed by high-explosive bombs weighing 4,000lbs, then the attic floors of the buildings were ignited by lightweight incendiary mixtures, and, at the same time, fire bombs weighing as much as 30lbs fell into the lower stories. Within a few minutes, huge fires were burning across the bombed area, which covered about eight square miles, and they merged so rapidly that, only a quarter of an hour after the first bombs had dropped, the whole airspace was a sea of flames as far as the eye could see. Five minutes later, at 1.20am, a firestorm arose of an intensity that no one would ever before have thought possible. Reaching more than a mile into the sky, it snatched oxygen to itself so violently that the air currents reached hurricane force, resonating like mighty organs with all the stops pulled out at once.

The fire burned like this for three hours. At its height, the storm lifted gables and roofs from buildings, flung rafters and entire advertising kiosks through the air, tore trees from the ground, and drove human beings before it like living torches. Behind collapsing facades, the flames shot up as high as houses, rolled like a tidal wave through the streets at a speed of more than 90 miles an hour, spun across open squares in strange rhythms, like spinning cylinders of fire. The water in some of the canals was ablaze. The glass in the tramcar windows melted; stocks of sugar boiled in the bakery cellars. Those who had fled from their air-raid shelters sank, in grotesque contortions, in the thick bubbles thrown up by melting asphalt. No one knows for certain how many lost their lives that night, or how many went mad before they died. When day broke, the summer dawn could not penetrate the leaden gloom above the city. The smoke had risen to a height of five miles, where it spread like a vast, anvil-shaped cumulonimbus cloud. A wavering heat, which the bomber pilots said they had felt through the sides of their planes, continued to rise from the smoking, glowing mounds of stone. Residential districts whose street lengths totalled 120 miles were utterly destroyed. Horribly disfigured corpses lay everywhere. Bluish little phosphorous flames still flickered around many of them; others had been roasted brown or purple and reduced to a third of their normal size. They lay doubled up in pools of their own melted fat, which had sometimes already congealed. The central death zone was declared a no-go area in the next few days. When labour gangs of prisoners and camp inmates could begin clearing it, in August, after the rubble had cooled down, they found people still sitting at the tables where they had been overcome by carbon monoxide.

Elsewhere, clumps of flesh and bone or whole heaps of bodies had cooked in the water gushing from bursting boilers. Other victims had been so badly charred and reduced to ashes by the heat, which had risen to a thousand degrees or more, that the remains of families consisting of several people could be carried away in a single laundry basket.